Implantable medical devices, such as prosthetic grafts or endovascular stents, are used frequently in medical procedures. For instance, endovascular stents have been found useful in the treatment and repair of blood vessels after a stenosis has been treated by percutaneous transluminal coronary angioplasty (PTCA), percutaneous transluminal angioplasty (PTA), or other medical procedure in which the patency and/or integrity of a vessel lumen is improved. Stents may also be used to provide patency/integrity of a vessel lumen across a stenosis in cases in which no initial PTCA or PTA procedure is performed. Stents have also garnered beneficial results in other applications. For instance, stents may also be implanted in other body lumens or vessels, such as the urethra, esophagus, bile duct, or the like in order to improve the patency/integrity of the body lumen and/or vessel.
Once a stent is placed in a body lumen, it may be desirable to promote tissue growth on and/or around the stent to insure healing after a medical procedure. Thus, there is an ongoing desire to provide improved stent structures, constituents and/or arrangements which promote tissue growth on and/or around a stent within a body lumen to insure suitable healing after implantation of the stent.
Additionally or alternatively, during some medical procedures it may be advantageous to provide a therapeutic agent, such as a pharmacological substance or drug, at the location in which the stent is positioned during placement of the stent. Stents incorporating a pharmacological substance have been devised for this purpose. Drug-releasing stent devices have shown great potential in treating coronary artery disease, as well as in other treatment situations. As the use of drug-releasing stent devices becomes more frequent, there is an ongoing desire to provide improved techniques involving the incorporation and/or release of a therapeutic agent, such as a pharmacological substance, for delivery with an endovascular stent.